Utilization of continuous loop rubber or elastomeric tracks as the ground engaging elements of mobile farm and construction implements and vehicles is known. Such tracks may be fabricated within a rubber molding press, much like common vehicle tires are molded. Such tracks offer durability and shock absorbing characteristics, while eliminating mechanical wear and tear and breakage associated with mechanically linked segmented tracks. A drawback or disadvantage of molded, continuous loop rubber tracks is that they are relatively expensive to fabricate, and may require frequent total replacement. In the event that such tracks are damaged, such tracks ordinarily cannot be repaired, but must be discarded and replaced at substantial expense. Expenses associated with molding rubber continuous loop tracks for use with track laying vehicles or construction equipment has lead to utilization of used construction vehicle tires as an inexpensive source of rubber tracks. It is known that the sidewalls of a 38-inch farm tractor tire may be cut away, leaving only the tread portion, approximately 18 inches wide. Such a tread loop, when stretched over a pair of 24-inch diameter hubs will provide approximately 71/2 feet of track surface for ground contact. Thus, a common farm tractor tire includes sufficient tread material to provide a ground engaging continuous loop track for a vehicle or mobile implement.
Utilizing the tread portion of construction or farm vehicle tires to supply such rubber tracks provides significant economic benefits. For example, a tractor tire having sidewall damage may be unusable as a tractor tire; but may have a tread portion in perfect condition which may serve as a continuous loop track. Such construction or farm vehicle tires often have a negative valve to an equipment operator needing usable tires, and may be obtained at little or no cost.
A track laying vehicle or implement typically has pairs of laterally opposed forward and rear track driving and guiding hubs. For example, where a track laying vehicle has a rearward pair of track driving hubs and a forward pair of track guiding hubs, the tracks are installed over the hubs so that each track extends forwardly and tangentially over the upper radial surface of the track guiding hub, thence extending 180.degree. around the forward radial surface of the track guiding hub, thence extending tangentially rearward along the ground to the lower radial surface of the rear track driving hub, thence extending radially 180.degree. to the upper radial surface of the track driving hub, thence extending forwardly to complete a continuous circuit. Where large construction vehicle tires, such as a 38-inch tractor tire, are used as the source material for a continuous loop track, it is known that pairs of common automobile tires may serve as such track guiding and driving hubs. Where such tires are utilized as the track guiding or driving hubs, two configurations are known. In one such configuration the construction vehicle tire is narrowly cut to match the width of a single automobile tire, such tires serving as forward and rear hubs. Such configuration requires attachment of inwardly extending steel retainer tabs to the outer edges of the track. As such a track having steel retainer tabs travels in a circuit around the forward and rear tire hubs, the tabs hold the track in place over the outer peripheries of the hubs. A second known configuration constructs tire hubs out of paired automobile tires, stacked side by side. In such configuration, a single row of steel retainer tabs are fastened onto the interior surface of the track so that as the track travels in a circuit around the hubs, the tabs travel in progression through the annular channels between the tires, holding the track in place upon the tire hubs.
A drawback or functional deficiency of utilization of common tires as track driving and guiding hubs is that such hubs tend to "clog" when driven through mud or snow, resulting in loss of traction. Snow or mud tends to accumulate between the exterior radial surfaces of the tire hubs and the interior surface of the track, resulting in slippage, and interfering with delivery of power to the ground.
Another drawback or deficiency resulting from utilization of common tires as track driving and guiding hubs is the necessity of installing track retaining steel tabs or flanges upon the track. Ordinarily, a steel tabs or flange must be fastened by screws or bolts at six inch intervals around the entire circumferential length of the track. In order to utilize vehicle tires to drive a track cut from a 38-inch tractor tire, approximately 36 retainer tabs are necessary where dual stacked tire hubs are used, and 72 tabs are necessary where single tire hubs are used. Installing track retaining tabs upon a track is both time consuming and expensive. Utilization of tires as hubs is also undesirable because bolts or screws used to install track retaining tabs creates multiple wear points in the track. Bolts and screws extending into the track degrade the integrity of the track. Also, installation of track retaining tabs is an expensive and time consuming procedure. Also, such tabs slowly loosen and work their way out of the track, and must be replaced.
The instant inventive track assembly solves the above problems by providing a hub which allows inward ingestion of ground material such as mud and snow, preventing clogging and slipping; the hub being capable of securely retaining a track cut from a construction vehicle tire without installation of retainer tabs.